dimanche 27 juillet 2014

Animals that don't Exist

The Finless Fish

The finless fish,
Exocoetus sinfina, belongs to
the Exocoetidae,
commonly known as the flying flish. Unlike his relatives, who have
unusally developed pectoral fins which allow them to glide over the
water to escape predators, the finless fish is characterized by an
absence of lateral fins. Only the caudal fin (the tail fin) remains.

Like
all other fish, the finless fish moves forward by undulating its
body. However, due to the lack of lateral fins, it uses its gill
openings to change direction, opening and closing them to go right or
left. In addition to its natural swimming motion, the finless fish
can accelerate to speeds of up to 60 km/h (~37 mph) by violently
expelling water through its anus. However, due to the speed and the
lack of lateral fins, it can only slightly change direction while
maintaining its top speed.

Biologists
have emitted a number of hypotheses as to why the finless fish has
lost its lateral fins in the course of its evolution, but none have
been proven to this day. One of the most prominent ones, formulated
by Dr. Marcus Pescus, of the South-Asian
Institute
for Fishy Studies (SAIFS),
stipulates that the absence of lateral fins allows the finless fish
to explore the coral caves found in the tropical Asian oceans, its
natural habitat. The lack of lateral fins makes it easier for the
fish to extricate itself in case it gets stuck, and allows it to go
through smaller tunnels. However, it has recently been shown that
finless fish prefer open waters to coral reefs, and as such
coral-cave exploration would not exert any selective pressure on
them. Dr. Marcus now insists that Sinfina
used to frequent said caves, and only recently changed its habitat.

Another
theory stipulates that the absence of lateral fins makes its body
more hydrodynamic, allowing it to escape predators at greater speeds.
But it seems unlikely that the small gain in speed would warrant the
considerable decrease in mobility, as mobility is a much more
important factor in escaping predators than pure speed. Besides, a
number of finless fish die each season because of said lack of
mobility, when, trying to escape from danger, they propulse
themselves into rocks or boats. The force of this impact can be quite
substantial, and it is believed that the finless fish crashing into
their boats is what gave the Japanese the inspiration for their
Kamikaze fighters.